Loud-speaking device



July 28, 1925.

A. NYMAN LOUD SPEAKING DEVICE Filed Sept. 1 1922 2 Sheets-Sheet l INVENTOR Alexander Nyman WlTNESSES: 6%"

ATTORNEY Patented July 28,- 1925.

UNITED STATES ALEXANDER NYMAN, or 'W LKINSBURG,

. HOUSE-ELECTRIC 6'0 MANUFACTURING VANIA.

PENNSYLVANIA, 'ASSIGNOR -'1O WESTING- OOMPANY, A CORPORATION OF PENNSYL- LOUD-SPEAKING DEVICE.

Application nease tember 1c, 1922. Serial in. 688,548.

To all whom it ma 1/;0oncem:

Be it known thatI, ALEXANDER NYMA-If, a citizen of the United States, and a res1- dent of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and; useful Improvement in Loud-Speaking Devices,- of which the following is a specification. I

My invention relates to sound-reproducing apparatus, having particular relation to telephone transmitters or receivers.v One object of my invention ,is to provide a new embodiment of a loud speaking device, wherein signal currents are faithfully translated into sound waves, or vice versa, without distortion.

Another object of my invention is to provide sound reproducing apparatus, wherein the vibratory elements are caused to move in a substantially rectilinear direction only, thereby eliminating many of "the well known liildesirable effects characteristic of the prior art telephone apparatus employing rigidly mounted vibratory elements.

Still another object of my invention is to provide apparatus of the class described above, which is characterized by its extreme simplicity of arrangement and accessibil ty of parts requiring adjustment and WlllCh lends itself to inexpensive quantity production methods of manufacture, the several parts of which may be easily made in exlsting automatic machinery and may readily assembled with a minimum expenditure of time and of money.

According to my invention,-I providea telephone transmitter or receiver, wherem a pair of vibratory armature elements are employed which constitute the pole terminals of a permanent magnet. The vibratory elements are movable bodily in a substantially rectilinear direction between oppositely directed pairs of pole pieces, which are energized by a magnetizing winding carrying signal currents. The vibration of the armature member incident to the exci-.

tation of the magnetizing winding may be transmitted to a diaphragm member to produce sound waves, all as described more fully hereinafter.

With these and other objects and applications in "iew, my invention further consists in the nature, the mode of operation and the constructional details-hereinafter described and claimed and illustrated in the accompanying drawing, wherein: p

F igure 1 is a top plan view of one form of sound-reproducing apparatus embodying -my invention;

F 1g. 2 is a vertical longitudinal sectional view of the apparatus shown in Fig. 1,v

taken on the line 11-11 thereof;

Fig. 3 is a similar view taken on the line III-'III of Fig. 1.

Fig. 4 is a detail view of a metal blank or punching from which the yoke member may be formed.

In one embodiment of my invention, a permanent magnet 1 is provided having opposite end portions 2' and 3 facing one another in spaced relation. A vibratory armature construction 4 designed to be movable bodily in a substantially rectilinear direct1on is positioned in the space intermediate the end portions or poles 2 and 3 and is earned at its opposite ends by means of magnetizable spring members 5 and 6. The

latter members 5 and 6 arerespectively secured to the vertically extending portions 7 and 8 of L-shaped steel frames 9 and 11, the horizontally extending portions 12 and 13 of which are secured respectively, to the top sides of the end portions 2 and 3 of the magnet 1, as shown in the drawing.

The armature construction 4 comprises a pair of horizontally positioned magnetizable members 14 and 15 of rectilinear shape, the adjacent sides of which are mechanically connected by means of a member 16 of non-magnetizable material, for reasons which will be apparent hereinafter. The opposite sides of the armature members 14 and 15 are flexibly secured to the vertical portions 7 and 8 of the steel frames 9 and 11 by means of the spring connections 5 and 6, respectively, as just stated. magnetic circuit of the permanentmagnet 1 is thus extended by means of the paths provided through the several steel frames 9 and 11 and the flexible connecting means 5' and 6 to the armature members 14 and 15, respectively, thereby permitting the armature members 14 and 15 to serve as pole terminals for the permanent magnet 1.

The vibratably mounted armature members 14 and 15 may be caused to vibrate by means of an electromagnet structure 17 which is supported in the space intermediw The ate the ends2 and 3 of the permanentmagnet 1 by means of a frame 18 of non-magnetizable material, such as brass, which is rigidly secured to the vertical portions 7 and 8 of the steel frames 9 and 11, all as The yoke member 19 may be originally con-- structed from a punching or blank 21 of magnetizable material, as shown in Fig. 4, and comprises a central core portion 22 upon which the exciting coil 20 is mounted. The opposite ends of,the central core portion 22 are extended to form the portions 23 and 24'which terminate, respectlvely, in pairs of polar projections 25, 26, and 27, 28.

In the construction of the yoke member 19 from the blank 21, the end portions 23 and 24 are bent along the lines 23a and 24a, respectively, into upright position. The

legs or polar extensions 25 and 27 are then bent inwardly along-the lines 29 and 31, respectively, to cause a portion of the rejection 25 to be disposed immediately a ove a corresponding portion of the projection 27, the space 32 therebetween being determined by the relative positions of the lines 29 and 31.- The remaining projections 26 and 28 are similarly bent along the lines 33 and 34, respectively, to cause a portion of the projection 28 to be disposed immediately over a portion of the projection 26, thereby forming an air gap 35 which is positioned in alignment with the air gap 32, The construction of the yoke member 19 may, of course, be various y modified with in the scope of my invention as by employing a separate core for the magnetizing coil 20 which is rigidly secured to the end portions 23 and 24.

When the magnetizing coil 20 is excited by electrical'energ'y, a pair of magnetic circuits, as indicated by the dotted arrows a and 0 are established having the air gaps 32' and 35, respectively, therein, the magnetic flux traversing the air gaps being in opposite directions. The pairs of horizontalprojections'25, 27 and 28, 26 thus Constitute pairs of oppositely directed pole pieces for the electromagnet structure, 17.

In the complete assembly of my invention shown inFigs. 1, 2' and 3, the electromag-' netic structure 17, as'previously stated, is supported b the brass ring 18 which is secured to t e vertically jupright portions 23 and 24 of the yoke member 21, the magnetizable armature members 14 and 15 being disposed in the air gaps 32 and 35. The exact position o ftthe armature members 14 and 15 in the air gaps 32 and 35, respectively, is suchas to cause the several armature membersto be acted upon by balanced forces, as will be explained more fully hereinafter.

The magnetic circuit of the permanent magnet 1 between the armature members 14 and 15 now comprises a pair of parallel connected paths, as indicated by the solid line arrows in the drawing. The one magnetic circuit extends from the armature member 14'through a portion of the air gap 32, the

.pole piece 27, the upright ortion' 24, the

pole piece 28 and a portion 0 the airgap 35 to the armature member 15. Theother magnetic circuit extends from the armature member 14 through a portion of the air gap 32, the pole piece 25, the base portion 23, the pole piece 26 and a portion of the air gap 35 to the armature member 15.

When the magnetizingwinding 29 is notenergized, and when the armature members 14 and 15 are disposed in a substantially central position between: their corresponding pairs ofpole pieces, saidarmature members are acted upon by opposite. magnetic forces of substantially equal intensity. Hence the armature structure 4 is in abalanced condition.

ergized, a relative strong magnetic flux'is caused to traverse the air gaps 32and 35 between the several airs of poles, aSprcviously discussed. Vhen the flux established by the magnetizing winding 19 1s in a direction indicated by the dotted line arrows a, and a,, it isseen that the magnetic forces between the poles 25 and 28 and the armature members 14 and 15, respectively,

. I When the magnetizing winding 19 is enareincreased, whereas the magnetic forces between the poles 27 and 26 and thearmature members 14 and 15, respectlvely, are

diminished. The result is a rectilinear motion of the'armature toward the oles 25 and 28, which is resisted by the orce' of the springs 5 and 6.

However, when the direction of the currents through the magnetizing winding 20 is reversed, the magnetic forces of the lower poles 27 and 26 upon the armature members 14 and 15, respectively, areincreascd in the same proportion thatthe magnetic forces of the upper poles 25a'nd 28 upon thesaid armature members are decreased. Hence,

there is a rectilinear motion of the armature members 14 and 15in the opposite direction towards the lower poles 27 and 26, which motion is again resisted by the force ofthe springs 5 and 6.

In view of the foregoing, it is apparent that when the magnetizing winding 20 is supplied with vibratory energy, the armatures are vibrated in accordance with the 1 frequency and the intensity of such energy.

The vibratory motion of the armatures ofa connector 3 to cause thetranslation of the vibratory armature energy into sound waves. The periphery of the diaphragm 36 may be positioned between resilient washers 38 and 39, which, in turn, are carried by a non-magnetizable frame 41 secured .to the horizontal portions 12 and 13 of the steel frames 9 and 11, respectively, by meansof screws 42. The washers- 38 and 39 may be held in position by means ofv an annular member 43 adjustably secured to the supporting member 41 by a'thread connection. In-operation, the washers 38 and 39 serve merely as a resilient support for the diaphragm 36 and do not appreciabl restrict the motion of the periphery thereoi: allowing the diaphragm 36 to vibrate freely as a whole.

In order to simplify the description of my invention and to'acilitate a clear understanding of the same, I have eliminated from the description and drawings such portions of the complete structure as, for instance,'.the enclosing casing, which would beleadily understood by those skilled in the art'.

bodiment of my invention for the purpose of illustrating its principles of operation and. constructional arrangement, it is apparent that certain changes and modifications'may be made in the nature, the mode of operation and details of construction without de arting from the spirit of my invention. desire therefore, that only such limitations shall be imposed thereon as are indicated in the appended claims or demanded by the prior art.

I claim as my invention: .1. In combination,-- a yoke member'providing paths for a pair of interconnected magnetic circuits having air gaps, one individual to each circuit, means for establishing a magnetic .flux in said magnetic circuits, said .air gaps being so arranged that the magnetic fluxtraversing one air gap is in opposite direction tothat traversing the other, and a permanent magnet having pole pieces of opposite polarities vibratably positioned in said air gaps, respec-' tively.

. 2. In combination, a yoke member pro- .viding paths for a pair of parallel magnetic circuits having air gaps, one individual to each circuit, means for establishing a varying magnetic flux in said magnetic circuits, the magnetic flux traversing one air gap being in an opposite direction to that traversing the other, and a permanent ma et having pole pieces, of opposite sign vlbratably positioned in saidair gaps, respectively, the

I magnetic flux emanating from one pole piece thereby .that the pole ing magnetic flux in said magnetic circuits,

said air gaps being so arranged that the magnetic ,flux traversing each is in opposite directions, a permanent magnet, magnetizable. armature members constituting pole pieces for said permanent magnet vibrataably positioned m said air gaps and nonmagnetic means for mechanically connecting said armature members.

4. In combination, a permanent magnet, a pair of vibratably positioned armature members constituting opposite oles for said permanent magnet, a pair 0 pole pieces disposed uponopposite sides of each armature member in such manner as to provide air gaps'therebetween, and a yoke member associating said pole pieces in such relation that the pole pieces of one pair are disposed in opposite relation to the f pole pieces of the other pair.

5. In combination, 'a permanent magnet, a pair of mechanically connected vibratably' positioned armature members constituting While I have described .a preferred em- 'vide air gaps therebetween, a yoke member,

and a winding thereon, said yoke member associating said polepieces in such relation ieces of one pair are oppositely" dis ose with respect to the, pole pieces oft e other pair.

6'. In combination, a permanent magnet, a pair of vibratably positioned armature members constituting opposite poles for said permanent magnet, and a yoke member carrying an exciting coilandhaviug divided polar projections forming pairs of pole pieces of opposite signyone .pairof pole pieces being provided for each armature member and disposed upon opposite sides thereof, the pole pieces of one 'pair being oppositely dis osed with respect to the polepleces of anot er pair. l

7 In combination, apermanent-magnet,

a pair of vibratably positioned armature members constituting opposite poles for said permanent magnet, means for causing said members to vibrate in unison, and ayoke member comprising a-central portion carrying-an exciting coil and end portions having divided polar projections, one pair of poles being associatedwith each armature member and disposed adjacent to opposite sides thereof, the poles of one pair being oppositely disposed With'respect to the poles of another pair. I

' 8. In combination, a yoke member provided with a central core portion and having divided polar projections extending from opposite ends of said central portion,

the ends of the projections from opposite ends being disposed one above the other to form pairs of spaced poles of opposite po larity, said pairs of poles being oppositely arranged, a permanent-magnet, an arma-' ture member vibratably positioned in the space intermediate each pair of poles in balanced relation thereto, said armature members constituting pole pieces for said permanent magnet, and an exciting coil encircling said core portion and carrying currents tending to unbalance the balanced relation of said armature members.

9. In combination, a yoke member provided with a central coreportiop and having divided polar projections extending from opposite ends thereof, the ends of the projections from opposite ends of said core being disposed one above the other to form vided with a central core portion and with divided polar projections extending from I opposite ends thereof, the ends of the projec'tions from opposite ends of said core. being' disposed one above the other to form pairs of spaced poles of opposite polarity, said pairs of poles being oppositely arranged, a permanent magnet, armature members having corresponding portions disposed in the space intermediate said poles and movablebodily in a substantially rectilinear .direction toward and away from the respective poles and having other portions secured-to the ends of the permanent magnet, non-magnetic means mechanically connecting said armature members to cause the same to vibrate in unison, and an exciting coil encircling said. central core portion.

11. In combination, a yoke member pro- .vided with a central core portion having a pair of divided polar projections extending from opposite ends thereof, the ends of said projections from opposite ends of said, core portionbeing "disposed one above 'the' other toform pairs of spaced poles of opposite polarity, said pairs of poles being opposite magnetizable members disposed in the space intermediate said poles and movable bodily tion, non-magnetic means mechanically com 1 1y arranged, a permanent magnet, vibratory I necting said armature members to cause the same to vibrate as a unit, flexible magnetizabIe means for securing said armature mem-' ALEXANDER NYMAN.

05. therein in a substantially rectilinear direc- 

